Java 8 streams groupby and count multiple properties

I have an object Process that has a date and a boolean error indicator. I want to get a count of total processes and a count of processes with errors for each date. So for example Jun 01 will have counts 2, 1; Jun 02 will have 1, 0 and Jun 03 1, 1. The only way I have been able to do this is streaming twice to get the counts. I have tried implementing a custom collector but haven't been successful. Is there an elegant solution instead of my kludgy method?